13 citations · 27 across the 20 of their papers we have counts for
21 papers
POSEIDON III: The Aligned Orbit of the Hot Neptune Around the Hot Star WASP-195
Juan I. Espinoza-Retamal, Joshua N. Winn, Rafael Brahm +33
Stellar obliquities provide important clues as to the formation and migration histories of planetary systems, but measurements remain scarce for Neptune-mass planets, especially th…
Spin-Orbit Alignment of Two Neptune-size Planets Younger than 500 Myr: TOI-560 b and TOI-5082 b
Elina Y. Zhang, Fei Dai, Andrew W. Howard +25
Stellar obliquity measurements provide a direct probe of planetary system dynamics, but remain sparse for Neptune-size planets, particularly at young ages. We present Rossiter-McLa…
TOI-4495: A Pair of Aligned, Near-Resonant Sub-Neptunes that Likely Experienced Overstable Migration
Mu-Tian Wang, Fei Dai, Hui-Gen Liu +24
We report the discovery of a sub-Neptune and a Neptune-like planet (, ) orbiting the F-type star TOI-449…
A Test of Substellar Evolutionary Models with High-Precision Ages from Asteroseismology and Gyrochronology for the Benchmark System HR 7672AB
Yaguang Li, Michael C. Liu, Trent J. Dupuy +35
We present high-precision measurements for HR~7672AB, composed of a Sun-like (G0V) star and an L~dwarf companion. Three nights of precise (70 cm/s) radial velocity (RV) asteroseism…
The KPF SURFS-UP Survey I: Transmission Spectroscopy of WASP-76 b
Aaron Householder, Fei Dai, Aurora Kesseli +25
We introduce the KPF SURFS-UP (Spectroscopy of the Upper-atmospheres and ReFractory Species in Ultra-hot Planets) Survey, a high-resolution survey to investigate the atmospheric co…
TOI-880 is an Aligned, Coplanar, Multi-planet System
Elina Y. Zhang, Huan-Yu Teng, Fei Dai +22
Although many cases of stellar spin-orbit misalignment are known, it is usually unclear whether a single planet's orbit was tilted or if the entire protoplanetary disk was misalign…
A Hot Jupiter with a Retrograde Orbit around a Sun-like Star and a Toy Model of Hot Jupiters in Wide Binary Star Systems
Steven Giacalone, Andrew W. Howard, Ryan A. Rubenzahl +21
We report an observation of a transit of the hot Jupiter (HJ) KELT-23A b with the Keck Planet Finder spectrograph and a measurement of the sky-projected obliquity () of its Sun-…
Stellar Obliquity of the Ultra-Short-Period Planet System HD 93963
Huan-Yu Teng, Fei Dai, Andrew W. Howard +24
We report an observation of the Rossiter-McLaughlin (RM) effect of the transiting planet HD 93963 Ac, a mini-Neptune planet orbiting a G0-type star with an orbital period of $P_{\r…
K-dwarf Radius Inflation and a 10-Gyr Spin-down Clock Unveiled through Asteroseismology of HD 219134 from the Keck Planet Finder
Yaguang Li, Daniel Huber, J. M. Joel Ong +26
We present the first asteroseismic analysis of the K3\,V planet host HD~219134, based on four consecutive nights of radial velocities collected with the Keck Planet Finder. We appl…
TOI-6324b: An Earth-Mass Ultra-Short-Period Planet Transiting a Nearby M Dwarf
Rena A. Lee, Fei Dai, Andrew W. Howard +71
We report the confirmation of TOI-6324 b, an Earth-sized (1.059 0.041 R) ultra-short-period (USP) planet orbiting a nearby (20 pc) M dwarf. Using the newly com…
An Obliquity Measurement of the Hot Neptune TOI-1694b
Luke B. Handley, Andrew W. Howard, Ryan A. Rubenzahl +9
We present spectral observations of the multiplanet host TOI-1694 during the transit of TOI-1694b, a 26.1 hot Neptune with a 3.77-day orbit. By analyzing radial velociti…
The Compositions of Rocky Planets in Close-in Orbits Tend to be Earth-Like
Casey L. Brinkman, Lauren M. Weiss, Daniel Huber +54
Hundreds of exoplanets between 1-1.8 times the size of the Earth have been discovered on close in orbits. However, these planets show such a diversity in densities that some appear…
The HD 191939 Exoplanet System is Well-Aligned and Flat
Jack Lubin, Erik A. Petigura, Judah Van Zandt +25
We report the sky-projected spin-orbit angle for HD 191939 b, the innermost planet in a 6 planet system, using Keck/KPF to detect the Rossiter-McLaughlin (RM) effect. Planet b…
Asteroseismology of the Nearby K-Dwarf Draconis using the Keck Planet Finder and TESS
Marc Hon, Daniel Huber, Yaguang Li +76
Asteroseismology of dwarf stars cooler than the Sun is very challenging due to the low amplitudes and rapid timescales of oscillations. Here, we present the asteroseismic detection…
TESS Giants Transiting Giants. VI. Newly Discovered Hot Jupiters Provide Evidence for Efficient Obliquity Damping after the Main Sequence
Nicholas Saunders, Samuel K. Grunblatt, Ashley Chontos +53
The degree of alignment between a star's spin axis and the orbital plane of its planets (the stellar obliquity) is related to interesting and poorly understood processes that occur…
KPF Confirms a Polar Orbit for KELT-18 b
Ryan A. Rubenzahl, Fei Dai, Samuel Halverson +24
We present the first spectroscopic transit results from the newly commissioned Keck Planet Finder on the Keck-I telescope at W. M. Keck Observatory. We observed a transit of KELT-1…
Obliquity Constraints for the Extremely Eccentric Sub-Saturn Kepler-1656 b
Ryan A. Rubenzahl, Andrew W. Howard, Samuel Halverson +25
The orbits of close-in exoplanets provide clues to their formation and evolutionary history. Many close-in exoplanets likely formed far out in their protoplanetary disks and migrat…
An Earth-sized Planet on the Verge of Tidal Disruption
Fei Dai, Andrew W. Howard, Samuel Halverson +95
TOI-6255~b (GJ 4256) is an Earth-sized planet (1.079 ) with an orbital period of only 5.7 hours. With the newly commissioned Keck Planet Finder (KPF) and CARMEN…
A Testbed for Tidal Migration: the 3D Architecture of an Eccentric Hot Jupiter HD 118203 b Accompanied by a Possibly Aligned Outer Giant Planet
Jingwen Zhang, Daniel Huber, Lauren M. Weiss +31
Characterizing outer companions to hot Jupiters plays a crucial role in deciphering their origins. We present the discovery of a long-period giant planet, HD 118203 c ($m_{c}=11.79…
The OATMEAL Survey. I. Low Stellar Obliquity in the Transiting Brown Dwarf System GPX-1
Steven Giacalone, Fei Dai, J. J. Zanazzi +31
We introduce the OATMEAL survey, an effort to measure the obliquities of stars with transiting brown dwarf companions. We observed a transit of the close-in ($P_{\rm orb} = 1.74 \,…
Staring at the Sun with the Keck Planet Finder: An Autonomous Solar Calibrator for High Signal-to-Noise Sun-as-a-Star Spectra
Ryan A. Rubenzahl, Samuel Halverson, Josh Walawender +11
Extreme precision radial velocity (EPRV) measurements contend with internal noise (instrumental systematics) and external noise (intrinsic stellar variability) on the road to 10 cm…